Sentence intelligibility in noise for listeners with normal hearing and hearing impairment: Influence of measurement procedure and masking parameters La inteligibilidad de frases en silencio para sujetos con audición normal y con hipoacusia: la influencia del procedimiento de medición y de los parámetros de enmascaramiento

Abstract

Speech intelligibility measurements strongly depend on several procedural parameters. In order to obtain comparable results from different test procedures, these parameters must be investigated as to which should be standardized and which could be set freely. This study investigates the influence of noise level, noise type, and presentation mode on speech reception thresholds (SRTs), and intelligibility function slopes in noise for normal-hearing and hearing-impaired subjects. The noise presentation level had no significant influence on either SRTs or slope values, provided that the presentation level exceeded hearing threshold. Two stationary, speech-shaped noises produced identical results. Speech-simulating fluctuating noise yielded about 14 dB lower SRTs for normal-hearing subjects and about 10 dB lower SRTs for 20% of the heating-impaired subjects. Of the hearing-impaired subjects, 30% did not benefit from the modulations and showed similar SRTs as for stationary noise. Using continuous noise yielded lower SRTs compared to gated noise. However, the difference between the results in continuous and gated noise was not significant for the hearing-impaired subjects. A presentation level of 65 dB SPL (normal-hearing subjects) or 80 dB SPL (hearing-impaired subjects) and an interfering noise with a spectrum similar to the mean long-term average speech spectrum (LTASS) is suggested for comparable adaptive measurement procedures. A fluctuating, speech-shaped noise is recommended to differentiate between subjects.

Advanced Beamformers for Cochlear Implant Users: Acute Measurement of Speech Perception in Challenging Listening Conditions

“…Sentences were presented in uncorrelated noise at an overall level of 65 dB SPL, with each loudspeaker calibrated for the same free-field presentation level. The OLSA noise is composed of an unintelligible, randomly-aligned superposition of all words in the test corpus, and thereby reflects the long-term spectrum of the speech material [29]. The speech level changed adaptively, depending on the answers of the subject, and the SNR determined where a speech intelligibility rating of 50% was scored (i.e., the speech reception threshold, SRT).…”

A simulation framework for auditory discrimination experiments: Revealing the importance of across-frequency processing in speech perception

“…As expected, the recognition results are at chance level (10%-correct) at low SNRs and tend towards 100%-correct for high SNRs. Figure 8 depicts the simulated SRTs depending on the noise condition and the employed feature set alongside the empirical results from the literature (Wagener et al, 1999;Wagener and Brand, 2005). Table III reports the corresponding results in numerical form for all considered feature sets and, in addition, the effect of modulation which is reported TABLE I.…”

“…The stimuli, the empirical data, and the PEMO model data for the ADEs were taken from the literature (Moore et al, 1998;Derleth and Dau, 2000;Wagener and Brand, 2005;Jepsen et al, 2008). While the model and empirical data from the literature were measured using adaptive methods, the simulations using FADE were performed using a constant-stimulus method which is explained in detail in Sec.…”

“…The stimuli and the empirical data for the speech intelligibility experiment were taken from Wagener et al (1999) and Wagener and Brand (2005). In the sentence test from Wagener et al (1999), listeners needed to repeat sentences of five words with a fixed syntactical structure which were presented in noise.…”

“…In addition to the unmodulated test-specific noise condition, a condition with a singlespeaker modulated speech noise from a male speaker at normal level, the IRCA5 noise from Dreschler et al (2001), was considered. The corresponding empirical thresholds were taken from Wagener and Brand (2005).…”